In the master door operator with which the present invention finds particular application, a driving clutch mechanism is mounted to the outer face of a vertically movable gate on an elevator car for cooperation with a plurality of driven clutch mechanisms respectively mounted on the inner faces of vertically movable landing doors. When the gate is closed the driving clutch passes freely through the several driven clutches as the elevator car moves from one floor to the next. When, however, the car is at a landing and the gate is lifted, the driving clutch engages the driven clutch on the particular landing door initially to release the interlock on the landing door and then to lift the landing door as the gate is lifted. As the gate is lowered, the landing door is also lowered, and as the driving clutch is released from engagement with the driven clutch the landing door interlock is returned to the interlocked position thereby permitting the car to be moved.
The driving clutch mechanism disclosed in my said copending application employs a pair of springs to hold the driving clutch members in the extended clutching positions. Since some car gates and landing doors are relatively heavy, these springs and the associated hardware also had to be relatively heavy to prevent slippage between the gate and doors.
The driven clutch mechanism disclosed in my said copending application employs a substantial number of linkage arms and associated bearings making it relatively costly to manufacture and maintain.